1. Field of the Invention
The present invention relates to acrylamide polymer solutions and, more particularly, to a material which reduces the viscosity of acrylamide polymer solutions. Furthermore, the present invention relates to a process of preparing lower viscosity acrylamide polymer solutions using the viscosity reducing materials of the present invention and the use of these low viscosity .[.grafted starch.]. polymer solutions as dry strength additives for fibrous substrates such as paper.
2. Discussion of the Prior Art
Acrylamide polymers have been found useful as adhesives, coatings, and resins useful for improving the properties of paper. Acrylamide polymers can be applied as solutions, typically aqueous. The use of acrylamide polymer solutions has been hindered because of the generally high viscous nature of these solutions. Various procedures to reduce the viscosity of a acrylamide polymer solution have been utilized. One such method involves raising the temperature of the acrylamide solution. Another method is to reduce the overall percent solids of the acrylamide polymer in solution. Both of these alternatives are economically disadvantageous. Heating and maintaining the solution at an elevated temperature requires the use of complicated equipment. The use of more dilute solutions of acrylamide polymers is disadvantageous since it would require the application of larger amounts of solution to obtain the necessary amount of polymer application and would also require the transportation of more dilute solutions which is expensive.